SUMMARYAmmonium nitrate solution applied to the leaves of sugar-beet increased plant dry weight and uptake of nitrogen by the roots. Uptake of phosphorus by the roots of swedes, but not sugar-beet, grown with high phosphorus supply to the roots, was decreased by applying sodium phosphate solution to the leaves; uptake from a lower phosphorus supply to the roots was unaffected. Phosphorus applied to the leaves had no effect on dry weight. Potassium uptake by the roots of sugar-beet plants grown with high potassium supply to the roots was unaffected by painting the leaves with a potassium chloride solution, that of plants with an intermediate potassium supply was increased, and plants grown with a low supply to the roots absorbed almost all the available potassium so painting could not much increase uptake by the roots. Application of potassium to the leaves increased dry weight of plants with low or medium potassium supply to the roots and did not affect that of plants with a high potassium supply.The top: root ratio for phosphorus content in mg. per plant was greater for phosphorus absorbed via leaves than for phosphorus absorbed via roots. Increasing the phosphorus supply to the roots increased this ratio for phosphorus absorbed either via leaves or roots.Potassium absorbed by leaves was slightly more efficient in increasing dry weight than potassium absorbed at the same time by the root. A similar comparison was not possible for nitrogen or phosphorus.The results of these and previous experiments indicate that all the nitrogen and potassium and over 80 per cent. of the phosphorus applied to leaves was absorbed. The small amount of phosphorus remaining unabsorbed on the surface of the leaf was unaffected by phosphorus supply to the root.